Scaup engine

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Derek Dodds

New member
Well i was going to build a BBIII til i realized i needed more room with a few guys and the dog or dogs. Question is if you put a 4 stroke on the Scaup do you have to modify the motor well like on the BBIII. Looks like the Yamaha or Honda 40 are the lightest so thats what i'm thinking. Also i'm a little confused on scarfing the plywood sheets for the bottom and sides. Will 2 4x8 sheets (i.e. 16 feet scarfed) per side do it or will i need more? The materials list Joel at Devlin sent me calls for 2 4x24 sheets to make the sides and bottom.
 
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Most motor wells have to be made to fit the motor of choice. Not sure about the plywood..whether you will need another scarf joint or not.
 
Derek

My Scaup had a 40 Mariner and there was no interference at all but on my Brant II there was with a 30 hp Johnson. It is best to have your motor during the build process. The only real interference issue to note is some motor's cavitation plate will bang on the lower corners of the motor well when turned all the way and rotated into shallow water position. The cure for this is to put your motor on and turn it to the extremes and tilt it up and down taking note where it contacts the well, if it does. You can then trim off those corners. I did this on my BBII and it actually took very little trimming. The chunks I took off looked like little 2" pyramids. Somewhere I have pics and will post them if you decide to build.
 
I built a Snow Goose and am planning to build a Scaup this Spring. Two 4' x 8' sheets of plywood scarfed into a 4' x 16' sheet is ample, you don't need to scarf three sheets of plywood.

BTW, my partner and I were really nervous about scarfing, actully thought about buying 4' x 16' special plywood before we realized cost and shipping were killers. It turned out the scarfing was one of the easiest tasks in the project. We did the stack method where you stagger and stack the plywood, then power sand the bevel, it was easy and worked perfectly. I think Eric or someone had pictures and a good description of the process. It's way cool when you end up with two 4' x 16' sheets of plywood overnight.
 
Hey Eric i'm taking your advice and trying to locate a motor before i start building the Scaup. What size shaft lenght do you run? is a 20 inch ok or do i need to find a 15?

Derek
 
Derek. Assuming you want a 40 and above... I only studied 4 strokes so all this information may be erroneous re 2 stroke.

Yamaha makes (or made, I don't know if they still do) a 15" shaft in a 40. It was a manual (start & trim) unit however.

There is no other manufacturer that makes a 15" in 40 hp and above in 4 stroke. There are more shaft option below 40, but you'll want the 40.
 
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